The goal of vegetable breeding is to combine various desirable traits in a single variety/hybrid. Such desirable traits may include greater yield, resistance to insects or pests, tolerance to heat and drought, better agronomic quality, higher nutritional value, growth rate and fruit properties.
Breeding techniques take advantage of a plant's method of pollination. There are two general methods of pollination: a plant self-pollinates if pollen from one flower is transferred to the same or another flower of the same plant or plant variety. A plant cross-pollinates if pollen comes to it from a flower of a different plant variety.
Plants that have been self-pollinated and selected for type over many generations become homozygous at almost all gene loci and produce a uniform population of true breeding progeny, a homozygous plant. A cross between two such homozygous plants of different varieties produces a uniform population of hybrid plants that are heterozygous for many gene loci. Conversely, a cross of two plants each heterozygous at a number of loci produces a population of hybrid plants that differ genetically and are not uniform. The resulting non-uniformity makes performance unpredictable.
The development of uniform lines requires the development of homozygous inbred plants, the crossing of these inbred plants, and the evaluation of the crosses. Pedigree breeding and recurrent selection are examples of breeding methods that have been used to develop inbred plants from breeding populations. Those breeding methods combine the genetic backgrounds from two or more plants or various other broad-based sources into breeding pools from which new lines are developed by selfing and selection of desired phenotypes. The new lines are evaluated to determine which of those have commercial potential.
One crop which has been subject to such breeding programs and is of particular value is the pepper, which includes bell peppers. C. annuum is a herbaceous annual. The plant has a densely branched stem and grows to 1.5 to 5 feet in height. The fruit is green when unripe, then usually changing to red or brown. The species can grow in many climates; however, they thrive in warm and dry climates. Hybrid vigor has been documented in peppers, and hybrids are gaining increasing popularity among farmers throughout the world, especially in countries with plentiful labor (Berke, 1999).